P1511: MUCORMYCOSIS IN PATIENTS WITH HEMATOLOGIC DISEASES: HOW TO IMPROVE THE PROGNOSIS
Authors: Jieru Wang, Nuobing Yang, Sizhou Feng
Journal: HemaSphere (2023)

Topic: 30. Infections in hematology (incl. supportive care/therapy) Background: Mucormycosis is a serious disorder with severe inflammatory response and tissue damage caused by the infection of Mucorales. Mucormycosis usually occurs in immunocompromised population, high mortality of mucormycosis is one of the challenges facing in patients with hematologic diseases. Aims: Our aim was to study the prognostic factors and potent antifungal treatment of mucormycosis and describe the role of metagenomic next⁃generation sequencing (mNGS) in early diagnosis. Methods: A single-center retrospective study included patients with hematologic diseases and mucormycosis diagnosed by the 2019 EORTC/MSG criteria from March 2012 to September 2022. The primary outcome was 84-day all-cause mortality after diagnosis. We described the prognostic factors of mucormycosis in multivariate survival analysis, and investigated the application of different diagnostic methods. Results: Ninety-five patients were divided into three classifications, 27 patients (28.4%) with “proven” mucormycosis, 16 patients (16.8%) with “probable” mucormycosis, and 52 patients (54.7%) with “possible” mucormycosis diagnosed by mNGS. The median age was 44 (1-68) years. The most common primary diseases was acute leukemia (69.5%, n=66), and 31.6% of patients (n=30) received hematopoietic stem cell transplantation. The most common pathogen species was Rhizopus spp (34.7%, n=33). The most common infection type was pulmonary infection (84.2%, n=80), followed by rhino-orbito-cerebral infection (4.2%, n=4). Disseminated infection occurred in 8 patients (8.4%) and breakthrough infection occurred in 47 patients (49.5%). There were 13 patients (13.7%) receiving amphotericin B (AmB), 22 patients (23.2%) receiving posaconazole (Pos), and 60 patients (63.2%) receiving AmB plus Pos. A total of 9 patients (9.5%) underwent surgical treatment. With a median follow up of 79 (1-1015) days, the overall mortality rate at 42 days and 84 days was 33.7% and 44.2%, respectively. Multivariate survival analysis showed that diabetes and hypoxemia were independent risk factors of mortality at 84 days, while combination antifungal therapy (AmB plus Pos) was the independent protective factor. The additional mNGS test was performed in 23 (85.2%) proven patients and 4 (25.0%) probable patients, and pathogens detected by mNGS was consistent with traditional methods. All the possible patients were diagnosed by mNGS test, and the median interval from the onset of mucormycosis to diagnosis was shorter than proven and probable patients (14 d vs 24 d, P=0.038). Meanwhile, with comparable characteristics, manifestations and treatment strategies, the 84-day overall survival rate was similar in possible patients and probable patients (55.8% vs 50.0%, P=0.685), and there was no significant difference in the overall response rate (ORR) of effective antifungal drugs between patients in possible group and probable group (38.0% vs 31.3%, P=0.625). Summary/Conclusion: Mucormycosis is a life-threatening fungal infection in patients with hematologic diseases. Early identification and control of prognostic factors will contribute to the reduction in mortality risk of mucormycosis patients with hematologic diseases. mNGS is helpful to early diagnosis, and combination of AmB and Pos is an effective antifungal treatment. Keywords: Hematological malignancy, Fungal infection, Prognostic factor